Introduction:
Background Patients with difficult intravenous access (DIVA) present an ongoing challenge to providing emergency care and resuscitation. Of the 116.8 million ED visits in 2007 in the United States 27% required IV catheter placement. (1) In many cases, failure to obtain peripheral IV access necessitates central venous cannulation (CVC), which introduces an increased risk of immediate and delayed complications secondary to a more invasive procedure and incurs increased utilization of departmental resources. (2) Extrajugular vein cannulation is an alternative approach but is obtainable in less than 50% of patients and usually necessitates the involvement of a physician. (3) This approach also usually requires the patient to tolerate supine or Trendelenburg positioning, which may be difficult for many patients.
Bedside ultrasound provides an alternative method of obtaining venous access when traditional landmark methods fail.(4,5) However, ultrasound-guided peripheral IVs (USGPIVs) suffer from a failure rate of up to 8% in the first hour after placement and 47% within the first 24 hours after placement.(4,6,7) This is much higher than traditionally placed IVs, which have reported failure rates of only 6-32% after three days. (8,9) Dislodgement of an IV has the potential to threaten patient safety by interrupting delivery of medications and fluids and putting patients at risk of extravasation that can lead to ischemia and/or tissue necrosis.
There are limited data regarding the reasons for the higher rate of failure for IVs placed under ultrasound guidance. One possible explanation is ultrasound provides the ability to access vessels that are deeper and smaller than those visible or palpable on physical exam. In addition, USGPIVs are often placed in different locations. In one study comparing the two techniques, 74% of USGPIVs were placed in the basilic or brachial vein; whereas 86% of traditionally placed IVs were placed in the forearm, hand, or antecubital fossa. (10) Catheters that have to traverse through more subcutaneous tissue or are in atypical locations may be more likely to kink or dislodge suggesting the hypothesis that IV durability is affected by the characteristics of the vessel being cannulated. By analyzing the outcomes of IVs placed under ultrasound guidance, the current study set out to determine the influence of vessel depth, diameter, and location on IV longevity.